Potential-energy diagrams, for reactions

FIGURE 4.10 Potential energy diagram for reaction of fert-butyl cation with chloride anion. 

Like tert butyloxonium ion tert butyl cation is an intermediate along the reaction pathway It is however a relatively unstable species and its formation by dissociation of the alkyloxonium ion is endothermic Step 2 is the slowest step m the mechanism and has the highest activation energy Figure 4 8 shows a potential energy diagram for this step... 

Potential Energy Diagrams for Multistep Reactions The SnI Mechanism... 

POTENTIAL ENERGY DIAGRAMS FOR MULTISTEP REACTIONS THE Sn1 mechanism... 

FIGURE 4 12 Potential energy diagram for the reaction of tert butyl alcohol and hydrogen chloride according to the SnI mechanism... 

Sketch a potential energy diagram for the reaction of 1 heptanol with hydrogen bromide paying careful attention to the positioning and structures of the intermediates and transition states... 

Section 4 9 The potential energy diagrams for separate elementary steps can be merged into a diagram for the overall process The diagram for the reac tion of a secondary or tertiary alcohol with a hydrogen halide is charac terized by two intermediates and three transition states The reaction is classified as a ummolecular nucleophilic substitution, abbreviated as SnI... 

Reaction coordinate for a two-step reaction Fig. 4.1. Potential energy diagrams for single-step and two-step reactions. 

Fig. 18-4. The mechanism and potential energy diagrams for the reaction CHaBr + OH-(aq)— -CHjOH + Br (aq)...

Figure I.S. Reaction cycle and potential energy diagram for the catalytic oxidation of CO by O2.

Figure 3.13. Potential energy diagram for the forward and reverse reaction...

Figure 1. Qne-dinenslonal Lennard-Jcnes potential energy diagram for adsorption of a diatomic molecule (liydrogen). p denotes liie reaction coordinate.

Figure 1. Selectivity is determined by the relative difference in activation energy between two possible products, while the rates of reaction to product 1 or 2 are determined by the absolute activation barriers, AgJ and AG. Curve calculated assuming AG = 18 kcal moF and a temperature of 300 K. Inset is a simplified potential energy diagram for the conversion of a reactant into two parallel products [10]. (Reprinted from Ref [10], 2002, with permission from American Chemical Society.)...

Figure 2-9. Reaction scheme for the complete catalytic cycle in glutathione peroxidase (left). Numbers represent calculated reaction barriers using the active-site model. The detailed potential energy diagram for the first elementary reaction, (E-SeH) + H2O2 - (E-SeOH) + H2O, calculated using both the active-site (dashed line) and ONIOM model (grey line) is shown to the right (Adapted from Prabhakar et al. [28, 65], Reprinted with permission. Copyright 2005, 2006 American Chemical Society.)...

Fig. 27. Schematic potential energy diagrams for the reactions (a) Y + cyclopropane and (b) Y + propene (Ref. 22).

Fig. 32. Schematic potential energy diagram for the reaction of ground state Y(a2 D) with cis-2-butene. Energies of stationary points estimated from calculations on Y f C2H4.22 Energies of product asymptotes calculated from known thermodynamic values and calculated bond dissociation energies.22 31 34 156 157...

FIGURE 6.6 Potential energy diagram for the theory of electron transfer reactions. The activated complex is at S. For reasonably fast reactions, the reactant adheres to the lower curve and slithers into the product curve through the activated complex—that is, an adiabatic electron transfer occurs. 

This means that energy is released in this reaction. The potential energy diagram for the reaction is ... 

Figure 3.9. A potential energy diagram for a reaction that can occur in two different ways, producing two different products (P), one kinetically and the other thermodynamically controlled. R, reactant TS, transition state RI, reactive intermediate and P (P and Pr), product.

Figure 10. Potential energy diagram for the dehydrocyclization of 18 obtained from an Intrinsic Reaction Coordinate (IRC) calculation at B3LYP/6-31G. Note that the IRC starts at the TS but does not quite reach either ground-state structure (reactant-products).

A potential energy diagram for an endothermic reaction is shown in Figure 6.13. The reactants at the beginning of the reaction are at a lower energy level than the products. The overall difference in potential energy between reactants and products is the enthalpy change. 

Figure 6.14 is a potential energy diagram for this reaction. It includes several snapshots as the reaction proceeds. 

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